I've run 5 battery packs through the saw already. The batteries are getting a bit warm...but I don't know if that really matters. I'm happy with this saw. It's just what I was looking for. It's still no replacement for an average gas saw that can run a 18" bar, but it has its purpose.....for me the 10 or 15 minutes it takes to rough cut a medium size carving(and i do about 6 of these in a days work....so thats over an hour a day where I can limit my noise) It is not a saw for huge jobs, cutting lots of firewood or cutting 18" logs!! But It's a darn good saw to have on hand for small trees, limbing and odds and ends. I just hope it holds up.
...and I know someone said this somewhere, but this IS the same saw as the GreenWorks 80v. The Lowes version is about $75 cheaper and more easy to return if you're not happy with it.